(1) Field of the Invention
This invention relates to a one-way clutch, and more specifically to a retainer for a one-way clutch.
(2) Description of the Prior Art
When a one-way clutch (hereinafter abbreviated as "OWC") is incorporated and used in a rotating part of an industrial machine or the like, the OWC has heretofore been retained with a certain degree of drag torque relative to an outer or inner race in order to protect the function of the OWC from vibrations, inertia forces and the like.
When a sudden acceleration or deceleration occurs in the rotation of the outer race by way of example, sprags are caused to slip on the race surface of the outer race due to their inertia forces and frictional forces are developed accordingly. It is hence necessary to apply a frictional force, namely, a drag torque between an outer retainer and the outer race so that the outer retainer and outer race are always rotated as unitary members. This is required to transfer each movement of the outer race promptly to the outer retainer and at the same time to ensure free movements of the sprags. In order to obtain a certain degree of drag torque, the outer retainer has been subjected to cutting machining, namely, T-bar machining or I-bar machining or has been provided with spring members such as drag clips.
Since conventional retainers of the former type are partly cut off, their manufacturing costs are high and in addition, they involve a potential danger that the strength of the retainers themselves is adversely affected. When drag clips or the like are provided as separate members, more parts are required so that their manufacturing costs jump up and their assembly work is also cumbersome. Moreover, the areas of contact between a conventional retainer and the race surfaces of its associated inner and outer races are too small to achieve any stable drag torque.
U.S. Pat. No. 2,630,896 to Dodge discloses a retainer which is, as shown in FIGS. 1e, 4 and 4a, in the form of an oval cage 5" formed with a pair of parallel flanges 5"a, 5"a one at each of opposite circumferential edges of the cage 5" in an attempt to improve the strength of the retainer. However, because of these two flanges 5"a, 5"a, this prior art retainer is too rigid to achieve an adequate degree of resiliency required for a stable drag torque.